Circuit-opening device.



B0. SCHWEITZE-R & A. HERZ. CIRCUIT OPENING DEVICE. APPLICATION FILED MAY 29. 1912.

Patented Apr. 23, 1918.

owirnn s'ra'rns rarer orricn EDMUND O. SGI-IWEITZER AND ALFRED Z-ZER-Z, OF CI-ZICAGO, ILLINOIS.

CIRCUIT-OPENING DEVICE.

Application filed May 29, 1912.

To all whom it may concern:

Be it known that We, EDMUND O. SCHWEIT- Zen and ALFRED Hnaz, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Gircuit-Opening Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

Our invention relates to an improved circuit opening device and has as its principal objects an increased certainty of action, an increased rating for a given size of fuse, and increased safety for the operators.

A further object of our invention resides in the particular arrangement and combination of parts hereinafter described.

In the accompanying drawings, Figure 1 is a vertical central sectional view of our device;

Fig. 2 is a plan view of our device with the cover removed.

Fig. 3 is a detail cross sectional view of the fuse clamping members.

Referring more particularly to the drawings, 1 is an exterior casing preferably of cast iron; 2 is a cover for said casing provided with an internal ridge 3 and an eX- ternal depending flange 4. On the flange 1 is also a perforated ear such as 5. Between the upper edge of the casing 1 and the cover is a suitable packing 6. The aperture and the ear 5 receive a chain 7 which is attached at its lower end to a second ear 8 carlied on the body of the casing 1. A guard 9 is also attached to the outer surface of the case and projects over the cover so that in case of accidental explosion on the interior of the case the cover will not be completely blown 0h. The guard 9, however, extends suliiciently far above the top 2 so that the top may be removed without difiiculty. When the top is removed it is held by the chain 7 so as to prevent its falling to the ground. The case is further provided with lugs 1010 which are for the purpose of supporting the case 1 on a wall or on the cross arm of a pole. These lugs are offset from the case as shown so as to provide room for the cover when the case isattached to the wall. Two screws or studs 1111 project through apertures in the case for the purpose of supporting the interior mech- Specification of Letters Patent.

Patented Serial No. 790,512.

Apr. 23, 1218.

anism. A drain plug 12 is shown in the bottom of the casing.

fv ithin the case 1 is mounted a porcelain base or socket 18. his socket is provided with suitable apertures 1el1 l for receiving the screws 11-11. Plugs li -la are cemented into the apertures 1 l1%, the plugs 1l 1slhaving screw threaded engagement with screws 1111. At the points where the screws 111l enter the casing 1 copper guard plates %O- 4LO are placed. These plates are retained in position by means of pro je ctions ll-1 1 which are sunk into the face or the casing 1. heads d24.-2 are provided for the screws 11, these heads having sharp ridges i3 which will bite into the plates 412 and pinch the plates against the screws to prevent leakage. The apertures 1% are reduced in size after leaving the screws 1111 and extend entirely through the member 13, so that they may be used for retaining screws in case the interior mechanism is desired to be used without the surrounding casing. The member 13 is pro vided with an interior chamber 15 and with two smaller chambers 16 and 17 connecting with chamber 15. In each of the chambers 16 and 17 is mounted a terminal block 18 provided with a spring contact clip 19 and having a. binding screw 20 for retaining the ends of the wires 2121.

he casing 1 is especially designed to pro mote the introduction and connection of the wires 21 as follows: The case 1 is provider with an interior shelf 22 running entirely around the casing. Suitable insulators 23 are carried in chambers 5050 opening out of case 1 at the level of the shelf 22. These insulators are cemented in place and are carried at the same end of the case as the lugs 10. One of the wires 21 entering through its insulator 23 is led directly to its terminal 18 at the same end of the device at which the wire enters, as shown in Fig. 2, whereas the other wire 21 is run along the shelf 22 by the side of the socket member 13 to the other end of the device where it is connected with the remaining terminal block. Insulating spools 21 are preferably slipped over the wires 21 to avoid all chance of a ground between the wires and the case. As shown in Fig. 2 the shelf 22 is wider on three sides of the device than it is on the fourth side in order to provide room for the convenient running of the wires 21.

A plug member 24: is provided which occupies the chamber 15 in the socket 13. Plug member 24 has a cover 25 and a handle 26. Mounted on the plug 21 are lniife contacts 27 for engaging the blocks 18 and springs 19. The contacts 27 are also provided with lugs 28 to which fuse ribbon may be attached by a suitable screw such as 29. The plug 24 is made preferably of porcelain. Below the main portion of the plug is a separate clamping member 30 also preferably of porcelain. The clamping block 30 is drawn upwardly by the springs 31 and tie wires 32 It will be understood that two of the springs 31 are used at diagonally opposite corners of the plug member 24:, but that only one appears in Fig. 1. The ends of both tie wires, however, appear at the bot-tom of member 30. Intermediate the plug 2 1 and clamping member 30 is a fuse block 31 preferably of asbestos. he block 31 is provided with a groove indicated in dotted lines in which are placed two smaller fuse blocks 32 and 33 preferably of limestone, 32 appearing in dotted lines only. The block 33, however, extends somewhat below the face of the block 31 so as to come into engagement with the upper face of the block 30. Now the fuse 34 passes down the vertical sides of the plug 24 and is inserted between the blocks 32 and 33. Consequently fuse 3 1 is compressed between the blocks 32 and 33 owing to the engagement between the surfaces of the blocks 30 and 33.

A ridge or projection 35 appears in Fig. l and this projection is integral with the member 13 and extends along three sides of the chamber 15, there being a groove 36 in the plu and the members 31 and 33, into which the ridge 35 projects when the plug is in place, as shown in Fig. 1. The lower face of the block 30 moreover is provided with a projection 37 which either contacts with the upper face of the ridge 35 or comes into close proximity to it. Consequently when the plug 2% is in place, as shown in Fig. 1 the chamber 15 is divided into two parts. lVithin the two halves of the chamber 15 on the vertical end walls are glued two strips of mica 38 and 39. These strips are opposite the position of the vertical ends of the fuse 34: and extend up at least to the height of the top of the contact blocks 18, allowing the plug to be inserted without danger of making contact between the verti cal portions of the fuse while the plug is being inserted. An insulating shield 10 shown in dotted lines in Fig. 2, is placed inside the upper part of the casing 1 and extends down to or below the level of the shelf 22. This shield separates the wiring and the case 1 from the handle 26 so that an operator can remove the plug 2d without danger of shock.

A. special feature of our invention relates to the use of oil in the case 1. Ne normally fill the case with oil to the level of a line well up on the handle 26, so that all the operating parts are completely flooded. This improves the operation of the fuse device particularly in two ways. First it increases the rating of a given fuse by reducing the temperature. For this reason a smaller or lighter fuse may be used for a given normal current. Since the amount of current flowing at the time the operation of a fuse on a short circuit isproportional to the mass of the fuse, it will be seen that this reduction in the size of the fuse is highly desirable.

The oil further improves the action of the fuse on account of its insulating qualities.

It will be understood that while we have described and shown the preferred form of our device that we contemplate all such modifications and rearrangements of our invention as are electrically and mechanically equivalent thereto.

Having thus described our invention, what we claim is:

1. A cut-out device comprising in combination, an outer casing open at its top and provided with an internal horizontal shelf, a receptacle mounted within the casing and carried thereby, wires entering the casing and the receptacle and being disposed along said shelf between the casing and the receptacle, said receptacle having contact making elements connected to said wires and the receptacle being open at its top to receive a fuse holding structure.

2. In a fuse device in combination, a casing provided with an internal shelf running along three sides of said casing, insulators mounted in adjacent corners of said casing at the level of said shelf, a wire entering said casing through one of said insulators and disposed along said shelf on one side of said casing, and a second wire entering the second of said insulators and disposed along said shelf on two sides of said casing.

3. A cutout device comprising in combination, an outer casing provided with an internal horizontal shelf, an insulating shield loosely mounted in said casing within said shelf, and wires disposed along said shelf between said casing and said shield and extending through said shield.

In witness whereof, we hereunto subscribe our names this 18th day of May, A. D., 1912.

EDMUND O. SCHVVEITZER. ALFRED HERZ. Witnesses:

A. L. Jones, A. S. DENNISON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O." 

